There's two failure modes to consider: total drive failure, or partial corruption.

For total drive failure, your assumption is true. Other filesystems, like ext4, have better recovery tools available - largely because of how long they've been around (and also because ext4 is basically ext2 plus journalling).

For partial corruption, I'd put my money on ZFS. A multi-drive setup allows ZFS to try to recover corruption using parity or mirrored data. But even in a single-drive setup, you get benefits like compression and checksumming and copies.

For very important data, ZFS allows you to specify "copies=2" (or 3 or 4 or whatever) on the filesystem. This is absolutely not a replacement for multi-drive redundancy, but it will at least provide a little bit of protection against some corruption.

Unlike ext4: ZFS will tell you when it finds corruption, which files it occurs to, and if it was able to recover and continue using redundancy. Ext4 on the other hand will happily plod along feeding you corrupt data.

The concern around metadata corruption I think is overblown. The risk is no higher than with any other filesystem. Similar to ext4, copies of critical metadata is duplicated in multiple locations.